A message signaled interrupt (MSI) enables an input/output (I/O) device, sometimes also referred to herein as a peripheral device, or a requesting agent, in a microprocessor based system to request service. Historically, I/O devices employed dedicated interrupt pins to signal a request for service, but pin-based interrupts are expensive in terms of the number of pins required for chip set devices and in terms of the need to manage interrupt signals that are generated out-of-band with respect to the address, data, and control busses or interconnects between the I/O device and the chip set.